Cable puller and method

ABSTRACT

A cable puller and associated methods are shown. Useful example methods include pipe bursting using cable pullers as shown. Cable pullers and methods shown provide a mechanical advantage that increases an amount of cable pulled in one cycle. Selected examples are shown that include a pulley located on a distal end of a moving portion of an extending and contracting beam. The pulley and the mechanical advantage it supplies helps to improve the efficiency of the cable puller and reduce manufacturing cost of the cable puller.

CLAIM OF PRIORITY

This application is a continuation of and claims priority to U.S. Pat.No. 10,167,986 filed on Sep. 22, 2016, entitled “CABLE PULLER ANDMETHOD”, which claims the benefit of priority to U.S. ProvisionalApplication Ser. No. 62/233,875, filed on Sep. 28, 2015, the benefit ofpriority of each of which is claimed hereby, and each of which areincorporated by reference herein in its entirety.

TECHNICAL FIELD

Embodiments described herein generally relate to cable pulling. Specificexamples may include pipe bursting or pipe splitting using cyclic cablepullers.

BACKGROUND

Trenchless pipe replacement is useful for replacement of pipes or otherburied conduits without the need to excavate the length of pipe to bereplaced. An example of trenchless pipe replacement includes pulling acutting blade with an expander through the pipe to be replaced, andattaching a new pipe behind the cutting blade. The pipe to be replacedis split, and pushed into the surrounding soil, and the new pipe, ofequal or larger diameter, is pulled into the new space within the splitpipe. Splitters are commonly used for small diameter pipes, and forpipes of a material that lends itself to splitting. Another example oftrenchless pipe replacement includes pipe bursting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a cable puller in accordance with someembodiments of the invention.

FIG. 2A is a side view of a gripping device in accordance with someembodiments of the invention.

FIG. 2B is another side view of the gripping device from FIG. 2A inaccordance with some embodiments of the invention.

FIG. 3A is a perspective view of a splitter in accordance with someembodiments of the invention.

FIG. 3B is another perspective view of the splitter from FIG. 3A inaccordance with some embodiments of the invention.

FIG. 3C is cross section diagram view of the splitter from FIGS. 3A and3B in accordance with some embodiments of the invention.

FIG. 4 is an end view of a portion of a cable puller in accordance withsome embodiments of the invention.

FIG. 5 is a side view of a cable puller in use in accordance with someembodiments of the invention.

FIG. 6 is a flow diagram of a method of operating a cable puller inaccordance with some embodiments of the invention.

DESCRIPTION OF EMBODIMENTS

The following description and the drawings sufficiently illustratespecific embodiments to enable those skilled in the art to practicethem. Other embodiments may incorporate structural, logical, electrical,process, and other changes. Portions and features of some embodimentsmay be included in, or substituted for, those of other embodiments.Embodiments set forth in the claims encompass all available equivalentsof those claims.

FIG. 1 shows a cable puller 100 according to an example of theinvention. An extending and contracting beam 110 is shown, including astationary portion 112 and a moving portion 114. In one example, theextending and contracting beam 110 includes a hydraulic cylinder. In oneexample, the extending and contracting beam 110 is composed solely of ahydraulic cylinder, and no other supporting structure is used. Althougha hydraulic cylinder is used as an example, other extending andcontracting devices may be used, such as an electric motor drivenextender, etc. A portion of a cable 102 is shown within the cable puller100 to aid in description of other components of the cable puller 100and their functions.

A soil reaction plate 120 is further shown coupled to an end of theextending and contracting beam 110. In the example shown, a second soilreaction plate 122 is shown coupled at approximately 90 degrees to thesoil reaction plate 120. In one example, a pair or orthogonal reactionplates 120, 122 may be useful to abut against a side and a bottom of anexit pit in a pipe bursting or pipe removal application. Although tworeaction plates are shown in FIG. 1, the invention is not so limited.Other examples may include a single reaction plate, or no reaction plateat all. In some examples a reaction plate may be a separate componentfrom the cable puller.

In the example shown, the soil reaction plate 120 includes a slot 124the slot 124 is configured to allow the reaction plate 120 and in someexamples the second reaction plate 122 to be sideways mounted onto acable that may already be located within a pipe to be burst, with thecable 102 lying within an exit pit. In one example, the slot 124 islarge enough to accept a bursting head. More details of this example arediscussed in examples below with respect to FIGS. 4 and 5.

A pulley 130 is shown coupled to an end of the extending and contractingbeam 110 opposite from the reaction plate 120, or otherwise opposite alocation where a cable will exit the ground during a bursting or removaloperation. In the example shown, a pair of plates 132 are included toprovide improved guidance to the cable being pulled, and to protect auser from exposed rotating portions of the pulley 130. In one example, abolt or other retainer may be inserted or through holes 133 to furthercapture the cable 102 being pulled during an operation.

A cable gripping device 140 is shown coupled to the stationary portion114 of the extending and contracting beam 110. More details of the cablegripping device 140 are discussed below with respect to FIGS. 2A and 2B.In one example, a guide pulley 148 is located adjacent to the cablegripping device 140. The guide pulley 148 may be used to pull a looseend easily away from the cable puller 100 as the cable 102 exits thecable puller 100. An operator may stand at a distance of a number offeet away from the cable puller 100, and the guide pulley 148 easilykeeps the loose cable 102 from becoming tangled as the cable puller 100cycles through a number of strokes.

In operation, the moving end 114 of the extending and contracting beam110 is cycled back and forth to pull the cable 102 in a series ofstrokes. The cable gripping device 140 engages and releases the cable102 between successive strokes of the extending and contracting beam110. The pulley 130 provides a mechanical advantage to the extending andcontracting beam 110. Specifically, because the extending andcontracting beam 110 lengthens a portion of cable 102 on both sides ofthe extending and contracting beam 110 the mechanical advantage of thepulley doubles an amount of cable pulled in one cycle.

This can be useful in cable pulling, especially over long distancepulls. If an amount of cable pulled in a single cycle is too short, thecable may merely stretch out and spring back in each cycle, and abursting or splitting head may not move within the pipe to be burst atall. By using a heavier rated hydraulic cylinder, and doubling theamount of cable pulled for each stroke, the above detailed problem isavoided entirely, or greatly reduced.

Some cyclic cable pulling systems have employed the use of both apulling cable gripping device, and a holding cable gripping device tohold the cable in tension while the pulling cable gripping device cyclesback for another stroke. By using configurations of the presentinvention, an amount of cable pulled for each stroke is doubled. As aresult, in some examples, only a single cable gripping device is needed,because some amount of cable stretch can be accommodated with such along amount of cable being pulled for each stroke.

Using only one cable gripping device simplifies the cable puller 100 andreduces the cost of the machine. By doubling the amount of cable pulledfor each stroke, a bursting operation can performed much faster thanwith a shorter stroke cyclic puller.

In one example, a splitter 150 is attached to the stationary portionbefore the cable gripper. More details of the splitter 150 are discussedbelow with respect to FIGS. 3A-3C.

In one example, a pivot 162 is included to allow the extending andcontracting beam 110 to be oriented within a range of angles withrespect to the soil reaction plate 120. In one example, the pivot 162works in conjunction with a number of selector holes 170 and pins (notshown).

FIGS. 2A and 2B show close up views of an example of a cable grippingdevice 140. A first jaw 142 and a second jaw 144 are located oppositeone another, with a linkage mechanism 141 to apply a gripping force to acable. In one example, the linkage mechanism 141 is actuated by frictionin the cable, which pulls the second jaw 144 tight onto the cable. Inone example, a release trigger 146 is included on a portion of the cablepuller 100, and positioned to bump into the second jaw 144 at the end ofa contracting stroke of the extending and contracting beam 110. In thisway, the cable will be released, and the slack may be pulled tight by anoperator, who may pull the slack cable over the guide puller 148, andaway from the cable puller 100.

FIG. 2A shows a pair of plates 145 that may be included in selectexamples to protect from moving parts of the cable gripping device 140during operation. In one example the cable gripping device 140 may beconfigured to be capable of side loading. A space 143 is located betweenthe first jaw 142 and a side plate 145. In use, an operator may insert aside surface of a cable into the space 143, and then laterally betweenthe first jaw 142 and the second jaw 144. In many cases, it isconvenient to be able to side load a cable onto the cable puller 100 andinto the cable gripping device 140. As discussed above, cables may befirst pulled through a pipe to be replaced, and the cable puller 100 maybe dropped into an exit pit after the cable is already there. In such acase, it is desirable to be able to side load a cable into one or morecomponents of the cable puller 100.

FIGS. 3A-3C show an example of a splitter that may be included in oneembodiment of the invention. FIG. 3A shows a splitter base 152 and apulley 154 located opposite the splitter base 152. A pair of side plates156 are included to hold the pulley 154 in place.

In an operation such as pipe bursting or splitting, a pipe that is beingburst may instead start to be pulled out of the ground with the cablestill located inside the pipe. This may be undesirable, as the pipe mayfoul up the working of components of the cable puller 100 such as thepulley 130 or the cable gripping device 140.

FIG. 3B shows a blade 158 that is located in the path of a pipe that maybe undesirably pulled out of the ground. The blade 158 splits the pipeas it is pulled into the cable puller 100, and the spit pipe may be moreeasily removed from the cable puller 100 before it fouls up anydownstream components. In the example shown, the blade 258 is astationary blade, however, other examples such as a wheel cutter may beused.

In one example, the blade 158 is replaceable, such as if the blade 158becomes worn. In the example shown, the blade 158 is formed on a basethat slides down into a slot in the splitter base 152. In one example,the blade 158 is held in place in the slot by one or more spring loadedballs that correspond to a detent. FIG. 3C shows a ball 155 being biasedby a spring 153. The ball 155 is thereby urged into a detent 157 on thebase of the blade 158. In one example, if a blade 158 is to be replaced,a screwdriver or other tool may be wedged from underneath the blade 158or the splitter base 152 to dislodge the ball 155 from the detent 157.In other examples, the blade 158 may be gripped with pliers and pulledout with force sufficient to overcome the ball 155 and detent 157.Although a replaceable blade 158 is shown, other example of splitters150 may not include replaceable blades 158.

FIG. 4 shows a front view of the soil reaction plate 120. A pulley 160is shown attached to the stationary portion 112 adjacent to the soilreaction plate 120. In the example shown, the pulley 160 includes aninner groove 164 sized for a cable to be pulled, and an outer surface166 to guide a bursting head 200 around the pulley 160. In the exampleshown, the soil reaction plate 120 includes a slot 124 large enough toaccept a bursting head 200.

In operation, it is difficult to remove a bursting head from an end ofthe new pipe that is being pulled into the soil after the old pipe isburst or split. It is much easier to remove the bursting head from theend of the new pipe, if the bursting head is pulled a larger distanceinto the exit pit before ending the pull. By having a slot 124 largeenough to accept a bursting head 200, and an outer surface 166 to guidea bursting head 200 around the pulley 160, the bursting head can bepulled past the soil reaction plate 120, and further into the exit pit,to better facilitate the removal of the bursting head, and still have alarge amount of new pipe extending into the exit pit with which to workon.

FIG. 5 shows a diagram view of an example operation using a cable puller100 as described in examples above. An entry pit 402 and an exit pit 404are shown. A pipe to be replaced 410 is shown, and a new pipe 210 isbeing pulled in to replace the pipe to be replaced 410. A bursting head200 is shown coupled to a cable 420 and to the new pipe 210.

An example of a cable puller 100 is shown located in the exit pit 404.As described above, the extending and contracting beam 110 moves asindicated by arrows 430, and pulls the cable 420 over the pulley 130 atthe top of the extending and contracting beam 110. As described above, afirst portion of cable 422 and a second portion of cable 424 are bothlengthened by the motion 430 of the pulley 130 and the extending andcontracting beam 110. This feature doubles the amount of cable pulled ineach stroke. A loose end 426 of the cable may be pulled out of the wayof the cable puller 100 by a user between cycles.

FIG. 6 shows one example method of operating a cable puller as shown inFIG. 5. In operation 602, a cable is placed through a pipe to bereplaced having a bursting head attached to a distal end of the cable.In operation 604, the cable is routed around a pulley attached at adistal, moving end of an extending and contracting beam. In operation606, the cable is gripped on a stationary portion of the extending andcontracting beam, and in operation 608. the moving end of the extendingand contracting beam is extended. The mechanical advantage of the pulleyis used to double an amount of cable pulled in an extension of theextending and contracting beam.

To better illustrate the method and apparatuses disclosed herein, anon-limiting list of examples is provided here:

Example 1 includes cable puller, including an extending and contractingbeam, including a stationary portion and a moving portion, a soilreaction plate coupled to the stationary portion, a pulley attached at adistal end of the moving portion, and a cable gripping device attachedto the stationary portion.

Example 2 includes the cable puller of example 1, wherein the extendingand contracting beam includes a hydraulic cylinder to power theextending and contracting beam.

Example 3 includes the cable puller of any one of examples 1-2, whereinthe extending and contracting beam is a hydraulic cylinder.

Example 4 includes the cable puller of any one of examples 1-3, furtherincluding a guide pulley located adjacent to the cable gripping device.

Example 5 includes the cable puller of any one of examples 1-4, whereinthe soil reaction plate includes a slot large enough to accept abursting head.

Example 6 includes the cable puller of any one of examples 1-5, whereinthe soil reaction plate includes a vertical and horizontal reactionplate portion.

Example 7 includes the cable puller of any one of examples 1-6, whereinthe cable gripper is capable of side loading.

Example 8 includes the cable puller of any one of examples 1-7, furtherincluding a splitter attached to the stationary portion before the cablegripper.

Example 9 includes the cable puller of any one of examples 1-8, whereinthe splitter includes a stationary blade that is replaceable.

Example 10 includes the cable puller of any one of examples 1-9, whereinthe stationary blade is held in place with one or more spring loadedballs that correspond to a detent.

Example 11 includes 1 cable puller including an extending andcontracting beam, including a stationary portion and a moving portion, asoil reaction plate coupled to the stationary portion, a first pulleyattached to the stationary portion adjacent to the soil reaction plate,a second pulley attached at a distal end of the moving portion, and acable gripping device attached to the stationary portion.

Example 12 includes the cable puller of example 11, further including anactuator to disengage the cable gripping device during a cycle of theextending and contracting beam.

Example 13 includes the cable puller of any one of examples 11-12,wherein the extending and contracting beam is a hydraulic cylinder.

Example 14 includes the cable puller of any one of examples 11-13,wherein a beam angle with respect to the soil reaction plate isadjustable.

Example 15 includes the cable puller of any one of examples 11-14,wherein the first pulley includes an inner groove sized for a cable tobe pulled, and an outer surface to guide a bursting head around thefirst pulley.

Example 16 includes the cable puller of any one of examples 11-15,wherein the soil reaction plate includes a slot large enough to accept abursting head.

Example 17 includes a method, including placing a cable through a pipeto be replaced having a bursting head attached to a distal end of thecable, routing the cable around a pulley attached at a distal, movingend of an extending and contracting beam, gripping the cable on astationary portion of the extending and contracting beam, and extendingthe moving end of the extending and contracting beam and using themechanical advantage of the pulley to double an amount of cable pulledin an extension of the extending and contracting beam.

Example 18 include the method of example 17, further including routingthe cable around a stationary pulley located on the stationary portionof the extending and contracting beam and pulling the cable at an angleupwards out of an exit pit.

Example 19 includes the method of any one of examples 17-18, furtherincluding pulling the bursting head out of the ground at an end of arun, and through an opening in a reaction plate.

Example 20 includes the method of any one of examples 17-19, whereinpulling the bursting head out of the ground at an end of a run includespulling the bursting head through the opening in the reaction plate andaround at least a portion of the stationary pulley.

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment, and it is contemplated that such embodiments can be combinedwith each other in various combinations or permutations. The scope ofthe invention should be determined with reference to the appendedclaims, along with the full scope of equivalents to which such claimsare entitled.

The invention claimed is:
 1. A cable puller, comprising: an extendingand contracting beam including a first end portion and a second endportion; a pulley attached at a distal end of the first end portion,such that when in operation, the pulley moves back and forth as the beamextends and contracts; a single cyclic cable gripper including twogripping jaws, the single cyclic cable gripper attached to the secondend portion, wherein the single cyclic cable gripper is configured topull a cable through a length of pipe by gripping the cable with thegripping jaws on a beam extension, and releasing the cable on a beamcontraction; and a release trigger configured to release the singlecyclic cable gripper by bumping one of the two gripping jaws.
 2. Thecable puller of claim 1, wherein the extending and contracting beamincludes a hydraulic cylinder to power the extending and contractingbeam.
 3. The cable puller of claim 1, wherein the extending andcontracting beam is a hydraulic cylinder.
 4. The cable puller of claim1, wherein the single cyclic cable gripper is configured to accept sideloading of a cable.
 5. The cable puller of claim 4, further includingone or more side plates located adjacent to the single cyclic cablegripper.
 6. The cable puller of claim 1, further including a guidepulley located adjacent to the cable gripping device.
 7. The cablepuller of claim 1, further including a reaction plate coupled to thesecond end portion.
 8. The cable puller of claim 7, further including anangle adjustment pivot located between the soil reaction plate and theextending and contracting beam.
 9. The cable puller of claim 7, whereinthe soil reaction plate includes a slot large enough to accept abursting head.
 10. The cable puller of claim 7, wherein the soilreaction plate includes a vertical and horizontal reaction plateportion.
 11. The cable puller of claim 1, further including a splitterattached to the second end portion before the cable gripper as definedalong a cable pulling direction.
 12. The cable puller of claim 11,wherein the splitter is located before the pulley as defined along thecable pulling direction.